Formation mechanism of supramolecular hydrogels in the presence of L-phenylalanine derivative as a hydrogelator

摘要

A novel chiral hydrogelator,L-phenylalanine derivative can self-assemble in aqueous media at different pH values to form supramolecular hydrogels.The images of the FE-SEM indicate that different aggregates of TC_(18)PheBu in morphology were formed,which further lead to the formation of spherical crystallites as observed by polarized optical microscope(POM).The FT-IR spectra of the supramolecular hydrogels reveal that intermolecular hydrogen-bonding and hydrophobic interactions are the driving forces for the self-assembly of TC_(18)PheBu.Fluorescence spectra of TC_(18)PheBu in aqueous solutions in the presence of pyrene as a probe further confirm the importance of hydrophobic interactions for the self-assembly.The circular dichroism(CD)spectra of TC_(18)PheBu in supramolecular hydrogels in the presence of KF indicate that the hydrogen-bonding interaction can be disrupted by fluoride ions,which further confirm the importance of hydrogen bonding for the self-assembly of TC_(18)PheBu.